JP2018063345A - Optical element support and image drawing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical element support structure in which unevenness in fitting posture is suppressed irrespective of an error in the external dimensions of an optical element, and further provide an image drawing device free of misregistration of colors.SOLUTION: An optical element support comprises: a housing 40 provided with a first holding face 41 for holding a first face 181 of an optical element 18 in contact therewith and a second holding face 42 for holding at least a portion of a ridge line 182 away from the first face 181 of the optical element 18; a first pressing member 51 for pressing the optical element 18 against the first holding face 41; and a second pressing member 52 for pressing the optical element 18 against the second holding face 42. The intersection angle of an extrapolation face when each of the first holding face 41 and the second holding face 42 is extended by extrapolation is an acute angle. A first pressing position at which the first pressing member 51 applies a pressing force to the optical element 18 is closer to the second holding face 42 than the center of the optical element 18, and a second pressing position at which the second pressing member 52 applies a pressing force to the optical element 18 is farther away from the first holding face 41 than the center of the optical element 18.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an optical element support and an image drawing apparatus, and more particularly to an optical element support and an image drawing apparatus suitable for support when an optical element such as a prism or a mirror is provided.

  Conventionally, many optical elements have been used to optically reflect and refract light from a laser light source or the like. For example, taking an image drawing apparatus as an example, a wavelength-selective dichroic mirror is used as an optical element in order to align the optical axes of the three colors of green, red, and blue emitted from the laser light source unit substantially the same. Is provided. An error in the mounting posture of an optical element such as a dichroic mirror causes a color shift on the screen in, for example, an image drawing apparatus.

  As an example of a support structure for accurately mounting the optical element with respect to such a problem, the two surfaces of the predetermined surface of the optical element and the surface adjacent to the surface are pressed by a fixing spring, respectively. A technique is known in which the back surface side of each is in contact with and supported by each of the seating surfaces provided in the housing. Such a technique is described in, for example, JP-A-2016-126269.

JP 2016-126269 A

  As in the above prior art, in the support structure in which the two surfaces of the optical element are mounted in contact with the seating surface, if there is an error in the external dimensions, the contact position between the optical element and the seating surface is not constant and is fixed. There is a possibility that a rotational moment is generated in the optical element due to the pressing force by the spring and the reaction force received from the seat surface, and the optical element is attached in a state of being lifted from the seat surface. For example, when there is a positive squareness error, the optical element can be easily attached in a state where the ridge line on the side different from the seating surface side floats from the surface. On the other hand, when there is a negative squareness error, the optical element is easily attached with the ridge line on the seating surface side floating from the surface.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an optical element support and an image drawing apparatus in which variations in the mounting posture are suppressed regardless of errors in the external dimensions of the optical element.

  In order to achieve the above object, a first holding surface that has a casing, and that holds a first surface that is a predetermined surface of the optical element in contact with a part of the casing; A second holding surface is formed to contact and hold at least a part of the ridge line separated from the first surface on the second surface adjacent to the first surface, and presses the optical element toward the first holding surface; A first pressing member, and a second pressing member that presses the optical element toward the second holding surface, and an intersection angle between the first holding surface and the second holding surface is the first surface And an angle formed by the second surface.

  Alternatively, a housing provided with a first holding surface that holds and holds the first surface of the optical element, and a second holding surface that holds and holds at least a part of the ridge line away from the first surface of the optical element; A first pressing member that presses the optical element toward the first holding surface; and a second pressing member that presses the optical element toward the second holding surface. The intersecting angle of the extrapolated surface when inserted and extended is an acute angle, and the first pressing position at which the first pressing member applies pressure to the optical element is closer to the second holding surface than the center of the optical element. The second pressing position where the two pressing members apply pressure to the optical element is a position farther from the first holding surface than the center of the optical element.

  According to the present invention, it is possible to provide an optical element support that suppresses variations in the mounting posture regardless of errors in the outer dimensions of the optical element. Furthermore, in the image drawing apparatus to which the present invention is applied, the optical axes of the three colors of laser beams can be made substantially the same, so that it is possible to display an image with little color misregistration.

The top view which shows roughly the structure of the image drawing apparatus to which Example 1 is applied. The partial exploded perspective view which shows the structure of the support structure for the dichroic mirror of Example 1 The fragmentary sectional view which shows the support structure of the dichroic mirror of Example 1 The fragmentary sectional view which shows the shape of the holding surface provided in the housing | casing of Example 1. The fragmentary sectional view which shows the pressing position of the dichroic mirror of Example 1. The partial exploded perspective view which shows the structure of a support structure for the dichroic mirror of Example 2 The fragmentary top view which shows the positional relationship of the holding surface of the housing | casing of Example 2. FIG. The fragmentary sectional view which shows the positional relationship of the dichroic mirror of Example 2, and the corner | angular part of a holding surface The partial top view which shows the pressing position of the dichroic mirror of Example 2.

  Example 1 will be described using an image drawing apparatus to which the optical element support structure of the present invention is applied as an example.

    FIG. 1 is a schematic plan view showing the configuration of an image drawing apparatus 1 to which the optical element support structure of Example 1 is applied. The dotted line in the figure represents the optical axis of the laser light. The image drawing apparatus 1 according to the first embodiment includes a laser light source unit 10 that emits a laser beam for image drawing and a deflection mirror device 20 that deflects and scans the laser beam in two dimensions as main optical components. The housing 40 is a molded product that supports and fixes the laser light source unit 10 and the deflecting mirror device 20.

  First, the configuration of the laser light source unit 10 will be described. In the laser light source unit 10, three laser light sources 11, 12, and 13 having different wavelengths are arranged.

  The laser light source 11 is, for example, a semiconductor laser that emits green laser light. The green laser light emitted from the laser light source 11 passes through the collimator lens 14 and is converted into substantially parallel laser light, and then enters the dichroic mirror 17.

  The laser light source 12 is, for example, a semiconductor laser that emits blue laser light. The blue laser light emitted from the laser light source 12 also passes through the collimating lens 15 and is converted into a substantially parallel laser light, and enters the dichroic mirror 17.

  The dichroic mirror 17 is a wavelength-selective optical element having a function of reflecting the blue laser light emitted from the laser light source 12 while transmitting the green laser light emitted from the laser light source 11, and is transmitted through the dichroic mirror 17. Alternatively, the reflected two-color laser beams travel on substantially the same optical path in which the angles and positions of the optical axes are aligned, and enter the dichroic mirror 18.

  The laser light source 13 is a semiconductor laser that emits red laser light, for example. The red laser light emitted from the laser light source 13 passes through the collimating lens 16 and is converted into substantially parallel laser light, and then enters the dichroic mirror 18.

  The dichroic mirror 18 is a wavelength-selective optical element having a function of reflecting green and blue laser beams and transmitting only red laser beams. The three-color laser beams of green, blue and red that are transmitted or reflected by the dichroic mirror 18 travel as substantially the same laser beams having the same optical axis angle and position, and deflecting mirror device that scans the laser beams 20 is incident.

  Next, the deflection mirror device 20 will be described. The deflection mirror device 20 includes a reflection mirror 21 in the device, and has a function of vibrating the reflection surface about two axes. The deflecting mirror device 20 reflects the incident laser light and scans the screen 30 in two directions at a predetermined distance to draw an image.

  The support structure of the present invention is applied to fixing the dichroic mirrors 17 and 18 disposed in the optical path of the image drawing apparatus 1. Below, the specific support structure and its effect are demonstrated taking the dichroic mirror 18 as an example.

  FIG. 2 is a partial exploded perspective view showing the structure of the support structure for the dichroic mirror 18 according to the first embodiment. FIG. 3 shows the support structure for the dichroic mirror 18 according to the first embodiment in the section AA ′ of FIG. It is a fragmentary sectional view shown. In the figure, reference numeral 182 denotes a ridge line away from the reflection surface 181 of the dichroic mirror 18, which is a ridge line on the second holding surface 42 side on the back surface 185 of the reflection surface 181. Here, the ridge line means a line segment formed by the intersection of two adjacent surfaces. Specifically, the ridge line 182 is a line segment formed by the intersection of the second surface 186 of the dichroic mirror and the back surface 185 of the reflecting surface. Reference numerals 183 and 184 denote ridgelines on the second pressing portion 52 side and the second holding surface 42 side on the reflection surface 181, respectively.

  The housing 40 has a first holding surface 41 that holds the reflecting surface 181 that is the first surface of the dichroic mirror 18 and a second holding surface that holds a part of the ridge line 182 away from the reflecting surface 181 of the dichroic mirror 18 in contact with each other. 42. A pressing member 50 is inserted between the back surface 185 of the reflecting surface 181 of the dichroic mirror 18 and the housing 40. The pressing member 50 includes a first pressing portion 51 that presses the dichroic mirror 18 toward the first holding surface 41 and a second pressing portion 52 that presses the dichroic mirror 18 toward the second holding surface 42. As described above, the position and posture of the dichroic mirror 18 according to the first embodiment are defined by pressing the reflecting surface 181 against the first holding surface 41 of the housing 40 and the ridge line 182 against the second holding surface 42. . In the present embodiment, the first pressing portion 51 and the second pressing portion 52 are integrally formed on one pressing member 50, but the first pressing portion 51 and the second pressing portion 52 are on separate pressing members. May be provided. Further, the angle tolerance between the reflecting surface 181 of the dichroic mirror and its back surface 185 is manufactured with extremely high accuracy. Therefore, in the present embodiment, the reflection surface 181 is pressed against the first holding surface 41 of the housing 40 as the first surface of the dichroic mirror 18, but the back surface 185 is pressed against the first holding surface 41. It is good.

  This embodiment has two characteristic configurations. The first feature will be described with reference to FIG. FIG. 4 is a partial cross-sectional view illustrating the shapes of the first holding surface 41 and the second holding surface 42 of the housing 40 according to the first embodiment. The second holding surface 42 is an inclined surface that goes down toward the first holding surface 41, and the inclination has a height difference larger than the squareness tolerance of the dichroic mirror 18. When the first holding surface 41 and the second holding surface 42 are extrapolated and extended, the intersection angle θ of the extrapolated surfaces (extrapolated surfaces 401 and 402) becomes an acute angle, so that the reflecting surface 181 of the dichroic mirror and its reflection are reflected. The contact position between the dichroic mirror 18 and the second holding surface 42 is always set to the back surface 185 side without depending on the perpendicularity error between the two surfaces of the second surface 186 that is adjacent to the surface and faces the second holding surface 42. The ridgeline 182 can be defined. In this case, in the dichroic mirror 18, the ridge line 184 on the second holding surface 42 side of the reflecting surface 181 may be lifted from the first holding surface 41 due to the rotational moment generated by the reaction force received from the second holding surface 42. On the other hand, the ridge line 183 on the second pressing portion 52 side of the reflecting surface 181 does not float from the first holding surface 41. In this embodiment, the ideal angle between the two surfaces of the reflecting surface 181 and the second surface 186 of the dichroic mirror 18 is a right angle (extrapolated surfaces 401 and 403). Even in the case of an angle φ that is not a right angle, the intersection angle θ between the extrapolated surfaces when the first holding surface 41 and the second holding surface 42 are extrapolated and extended is set smaller than the minimum allowable value of the angle φ. The same effect can be obtained. Here, the minimum permissible value means the minimum permissible dimension, or the permissible difference between the reference dimension and the lower dimension which is the lower limit value of the dimension. Even if the intersection angle θ of the extrapolation surface is simply set smaller than the minimum allowable value of the angle φ, substantially the same effect can be obtained.

  The second feature will be described with reference to FIG. FIG. 5 is a partial cross-sectional view illustrating the pressing position of the dichroic mirror 18 according to the first embodiment. In the figure, a one-dot chain line 61 represents the center line of the dichroic mirror 18 parallel to the normal line of the reflecting surface 181, and a one-dot chain line 62 represents the center line of the dichroic mirror 18 on the center plane of the reflecting surface 181 and the back surface 185. The first pressing position 51A where the first pressing portion 51 of the pressing member 50 applies a pressing force to the dichroic mirror 18 is closer to the second holding surface 42 than the center line 61, and the second pressing portion 52 is the dichroic mirror 18. The second pressing position 52 </ b> A for applying a pressing force to the rear surface is closer to the back surface 185 than the center line 62 of the dichroic mirror 18. In this case, the rotational moment generated by the reaction force received from the second holding surface 42 is canceled by the rotational moment generated by the two pressing forces acting on the dichroic mirror 18, and the first holding surface of the ridgeline 184 of the dichroic mirror is canceled. Lifting from 41 is suppressed. As a result, the dichroic mirror 18 can be attached to the housing 40 in a state where the reflecting surface 181 is always in surface contact with the first holding surface 41 regardless of the error in the external dimensions of the dichroic mirror 18.

  Therefore, it is possible to provide a support structure for an optical element that suppresses variations in the mounting posture regardless of errors in the outer dimensions of the optical element. Furthermore, in the image drawing apparatus to which the present invention is applied, the optical axes of the three colors of laser beams can be made substantially the same, so that it is possible to display an image with little color shift.

  A second embodiment of the present invention will be described with reference to FIGS. The description of the already-explained configuration denoted by the same reference numeral in the drawing and the portion having the same function is omitted.

  FIG. 6 is a partial exploded perspective view showing the structure of the support structure for the dichroic mirror 18 of the second embodiment. 81L and 81R in the figure are the first holding surfaces of the housing 80 divided into two, and 71L and 71R press the dichroic mirror 18 from the back surface 185 side toward the first holding surfaces 81L and 81R, respectively. It is a 1st press part.

  In addition to the two characteristic configurations described in the first embodiment, the second embodiment further includes two characteristic configurations. First, the first feature will be described with reference to FIGS. FIG. 7 is a partial plan view showing the positional relationship of the holding surface of the housing 80 of the second embodiment. FIG. 8 is a corner portion of the holding surface of the dichroic mirror 18 of the second embodiment and taken along the line BB ′ of FIG. It is a fragmentary sectional view which shows positional relationship with these. The first feature of the second embodiment is that the first holding surface of the casing 80 is composed of 81L and 81R divided into two in the same plane, and the second holding surface 82 is divided into two. It is formed between the holding surfaces 81L and 81R. In this case, even if the corners 81LC, 81RC, 82C of the first holding surfaces 81L, 81R and the second holding surface 82 are rounded to avoid damage to the casing 80 and the mold during molding, As shown in FIG. 8, since the corner portions 81LC, 81RC, and 82C do not contact the dichroic mirror 18, the accuracy of the mounting posture of the dichroic mirror 18 is not impaired.

  Next, the second feature will be described with reference to FIG. FIG. 9 is a partial plan view showing the pressing position of the dichroic mirror 18 according to the second embodiment. The pressing member 70 includes three first pressing portions 71L and 71R facing the first holding surfaces 81L and 81R and the second holding surface 82, and a second pressing portion 72, and applies a pressing force to the dichroic mirror 18. The one pressing positions 71LA and 71RA and the second pressing position 72A are opposed to the first holding surfaces 81L and 81R and the second holding surface 82, respectively. In the present embodiment, all of the first pressing portions 71L and 71R and the second pressing portion 72 are integrally formed on one pressing member 70. However, all or some of these pressing portions are separately provided. It may be provided separately on the pressing member. With this second configuration, the dichroic mirror 18 does not have an imbalance in the rotational moment in the longitudinal direction, and the reflecting surface 181 is made the first holding surface 81L, regardless of the error in the external dimensions of the dichroic mirror 18. It is possible to attach the dichroic mirror 18 to the housing 80 in a state where both surfaces of the 81R are in surface contact.

  Therefore, also in Example 2 in which the moldability of the housing is improved, it is possible to provide an optical element support structure in which variations in the mounting posture are suppressed regardless of errors in the external dimensions of the optical element. Furthermore, in the image drawing apparatus to which the present invention is applied, the optical axes of the three colors of laser beams can be made substantially the same, so that it is possible to display an image with little color shift.

DESCRIPTION OF SYMBOLS 1 Image drawing apparatus 10 Laser light source part 20 Deflection mirror apparatus 30 Screen 40, 80 Case 50, 70 Press member 11, 12, 13 Laser light source 14, 15, 16 Collimating lens 17, 18 Dichroic mirror 181 Reflecting surface 182 From reflecting surface The distant ridge line 183 The ridge line 184 on the second pressing portion side of the reflecting surface The ridge line 185 on the second holding surface side of the reflecting surface The rear surface 186 of the reflecting surface The second surface 61 adjacent to the reflecting surface and facing the second pressing portion 61 Dichroic mirror A center line 62 parallel to the normal line of the reflecting surface of the dichroic mirror and the center lines 41, 81L, 81R on the reflecting surface of the reflecting surface of the dichroic mirror and the first holding surface 42, 82 The second holding surfaces 42C, 82C, 81LC, 81RC corner portions 51, 51L, 51R first pressing portions 52, 72 second pressing portions 51A, 71LA, 71RA first pressing positions 52A, 72A Second pressing position θ Crossing angle φ of extrapolated surface when extrapolating and extending first holding surface and second holding surface respectively Reflection surface of dichroic mirror and side surface on second holding surface side adjacent to the reflecting surface Angle between two surfaces

Claims (10)

  A first holding surface that holds a first surface, which is a predetermined surface of the optical element, in contact with a part of the housing; and a first holding surface adjacent to the first surface of the optical element. A second holding surface configured to contact and hold at least a part of the ridge line apart from the first surface on the two surfaces, the first pressing member pressing the optical element toward the first holding surface, and the second A second pressing member that presses the optical element toward the holding surface, and an intersection angle between the first holding surface and the second holding surface is formed by the first surface and the second surface. A support for an optical element, characterized by being smaller than an angle.   The optical element support according to claim 1, wherein the crossing angle is an acute angle.   The first pressing position at which the first pressing member applies pressure to the optical element is closer to the second holding surface than the center of the optical element, and the second pressing member applies pressure to the optical element. 3. The optical element support according to claim 2, wherein the pressing position is a position farther from the first holding surface than the center of the optical element.   The first holding surface is constituted by a holding surface divided into at least two in the same plane, and the second holding surface is formed between the divided first holding surfaces. The support of the optical element according to claim 3. The pressing position at which the first pressing member applies pressure to the optical element is a position facing the first holding surface,
The optical element support according to claim 4, comprising two or more pressing members facing each surface.   An image drawing apparatus that includes a casing, a light source, and an optical element that optically applies light from the light source, and that draws on the screen via the optical element. A first holding surface that contacts and holds the first surface, which is a predetermined surface of the optical element, and a ridge line separated from the first surface on the second surface adjacent to the first surface of the optical element. A second holding surface that holds at least a portion in contact is formed, a first pressing member that presses the optical element toward the first holding surface, and a second press that presses the optical element toward the second holding surface An image drawing apparatus comprising: a member, wherein an intersection angle between the first holding surface and the second holding surface is smaller than an angle formed between the first surface and the second surface.   The image drawing apparatus according to claim 1, wherein the intersection angle is an acute angle. The first pressing position at which the first pressing member applies pressure to the optical element is closer to the second holding surface than the center of the optical element.
The image drawing according to claim 7, wherein the second pressing position at which the second pressing member applies pressure to the optical element is a position farther from the first holding surface than the center of the optical element. apparatus.   The first holding surface is constituted by a holding surface divided into at least two in the same plane, and the second holding surface is formed between the divided first holding surfaces. The image drawing apparatus according to claim 8. The pressing position at which the first pressing member applies pressure to the optical element is a position facing the first holding surface,
The image drawing device according to claim 9, comprising two or more pressing members facing each surface.

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